Why Buses Are Being Equipped with Commercial Air Filtration Systems

Learn why eco-friendly buses equipped with commercial air filtration systems are being used as solutions to maintain good indoor air quality.

Bus Filtration News – As countries around the world continue to grapple with the problem of air pollution, which the World Health Organization (WHO) claims is responsible for 4.2 million premature deaths around the world, governments and private companies are turning to a variety of solutions to mitigate its effects. For example, we’re seeing a rise in eco-friendly buses engineered with commercial air filtration systems, some with a particle removal efficiency of 99.5 percent.

One such type of bus can be found in the United Kingdom, where the Go-Ahead Group, one of the UK’s largest bus and rail operators, has launched the Bluestar Bus, an air-filtering bus that cleans the air as it plies its daily route. The Bluestar Bus is capable of removing fine particulate matter in the atmosphere with an efficiency of up to 99.5 percent, effectively sucking up dirty air and releasing it as clean, purified air that’s safe to breathe.

Southampton has the honor of being the testing site of the Bluestar pilot program, which will run for a period of three months. The city has reportedly reached unhealthy levels of air pollution, making it the ideal environment for the Bluestar Bus. Throughout the trial period, the bus will be monitored carefully to measure how much particulate matter (PM) it can capture from the atmosphere.

If successful, the Go-Ahead Group is looking to apply the air filter technology to 4,600 more Bluestar Buses.

How Buses Affect Outdoor and Indoor Air Quality

Pollution from buses, cars, trucks, ships, and construction equipment are among the top causes or poor outdoor and indoor air quality. The combustion process, or the burning of fossil fuels, releases all kinds of airborne pollutants into the atmosphere that form smog and acid rain.

“The combustion process produces hydrocarbons, nitrogen oxides, nitrogen dioxides, and carbon monoxide among other airborne pollutants,” explains Camfil USA’s Charlie Seyffer, Manager of Marketing & Technical Materials for commercial air filters and 37-year ASHRAE member and active committee participant. “These pollutants, both gaseous and particulates, can stay suspended in the air for indefinite periods of time creating health problems for those exposed.”

These dangers are precisely why the Clean Air Act was passed in the United States, making it possible for the U.S. Environmental Protection Agency (EPA) to set and implement emission standards to control air pollution produced by passenger cars, heavy-duty trucks, construction and farm machinery, and buses among many others.

Over the last 40 years, the agency has largely succeeded in pushing automotive companies to release cleaner and more fuel-efficient cars, trucks, SUVs, and buses. Indeed, today’s generation of automobiles has never been cleaner, with some even moving to electric vehicle technology.

Why Commercial Air Filters Are Important in the Fight Against Air Pollution

The idea behind using commercial air filters in the Bluestar Bus is simple. By attaching air filters to the bus itself, the filtration system can capture the particles produced by the bus, as well as well as other pollutants in the air while the bus travels along its daily route.

The air filters on the bus basically trap airborne particles as they pass through the filter media—usually a fibrous material with a tight mesh-like weave. In an indoor setting, when this filter media is attached to a heating, ventilation, and air conditioning (HVAC) system, it captures and sometimes even attracts particulate matter, gaseous pollutants, chemical fumes, and odor-causing contaminants as they pass through the filter.

But the problem with taking air filters to an outdoor setting like what the Go-Ahead Group is doing, is that outdoor environments have a much larger variety, not to mention higher concentrations, of airborne pollutants compared to your typical indoor space of a home or building.

It remains to be seen if this experiment will be a net positive or a publicity stunt as some observers have stated.

Common Automobile Pollutants Captured by Commercial High Efficiency Air Filtration Systems

Air pollution produced by cars, trucks, buses, ships, and aircraft that are powered by fossil fuels is split into two categories which are primary and secondary pollution.

“Primary pollution includes pollutants that can go straight into the atmosphere, while secondary pollution refers to pollution that forms as a result of chemical reactions between gases and particles,” said Seyffer. “Either way, these airborne pollutants can be captured by commercial high efficiency air filtration systems.”

When it comes to buses and other fossil fuel-powered vehicles, watch out for some of these pollutants.

Particulate matter (PM) – Particulate matter includes liquid droplets and solid particles small and light enough to be carried by the airstream. Diesel engines are particularly notorious for generating high levels of PM, which line tailpipes in the form of soot.

Volatile organic compounds (VOCs) – VOCs are a cocktail of contaminants created from chemical interactions between individual compounds that can create ozone or other respiratory irritants. Ozone, the primary component of smog, is a naturally occurring gas; at high levels it can irritate the throat and lungs, causing coughing, wheezing and difficulty breathing.

Nitrogen Oxides (NOx) – NOx is unique for being both a primary and secondary pollutant. It’s known to irritate the lungs and immune system, exasperating respiratory illnesses such as pneumonia and asthma. NOx can also react with other airborne pollutants to form ozone and even PM.

Carbon monoxide (CO) – Carbon monoxide is perhaps the most recognized pollutant produced by buses, cars and trucks, and for good reason. Between 2010 and 2015, more than 2,000 deaths in the United States were caused by carbon monoxide poisoning.

Effectiveness of Commercial High Efficiency Air Filters at Capturing Vehicle Pollutants

Of course, it’s always a good idea for business owners to be proactive and install commercial high efficiency air filters in their buildings and facilities. Some air purification systems are equipped with a combination of high-efficiency particulate air (HEPA) filters and activated carbon filters providing the highest level of protection against both particulate matter and gaseous pollutants.

True HEPA filters are designed to capture and remove particulate matter at an efficiency of 99.97 percent down to particles 0.3 micron in size , which includes fine particulate matter, or PM1 and PM2.5, commonly generated by combustion engines. It also comes from the dust generated by friction on wheels and brake systems.

On the other hand, activated carbon filters act like sponges, absorbing gaseous pollutants like smoke and vehicle exhaust. Activated carbon is basically carbon heated to extremely high temperatures, which “activates” and shrinks the fiber material, turning it into a superabsorbent filter that traps gases and chemical fumes through a process called molecular filtration.

Choosing Air Purification Systems

For homes and buildings in locations with high levels of air pollution, such as areas near freeways, factories, and power generation facilities, air purification systems offer a way to keep the air in indoor spaces clean and safe to breathe. In addition, air filters protect building occupants from breathing in airborne pollutants from indoor sources, such as raw materials, chemicals, and processes like heating, lighting, and cooking. They also protect people from the transfer of contaminants produced through breathing or sneezing, such as the flu or common cold.

The sheer variety of pollution sources means that your choice of air filter for your facility or building must consider factors like the type of airborne pollutants inside and outside the facility or commercial building. Other important factors to consider are what the most common source of indoor air pollutants is and the size of the indoor spaces requiring air filtration.

Camfil USA can help you find the best commercial air filtration systems for your facility’s needs. Talk to our team to discuss which air filter is most suited for your containment requirements. You may also browse our product line on our catalog.